Conventional arrangements (e.g., conventional sensor arrangements) may be used to determine a characteristic of fluid within a container (e.g., a tank). For example, the conventional arrangements can be used to determine a temperature of the fluid, a pressure associated with the fluid, a density of the fluid, etc. An exemplary conventional arrangement as described in U.S. Pat. No. 6,234,019, the entire disclosure of which is incorporated herein by reference, may be affixed to a top portion of a tank, and can include a housing arrangement positioned within the tank. Such conventional arrangement also may include a first sensor positioned within the tank at a first fluid level of a sample fluid, in which the first sensor is adapted to detect a fluid pressure at the first fluid level, and a second sensor positioned within the tank at a second fluid level below the first fluid level, in which the second sensor is adapted to detect a fluid pressure at the second fluid level. Moreover, the conventional arrangement includes a transmitter which is adapted to communicate with the first sensor and with the second sensor, and a calculating device that is coupled to the transmitter. The transmitter is further adapted to generate signals corresponding to the density of the sample fluid, and the calculating device is adapted to calculate the density of the sample fluid based on such signals. Another similar conventional arrangement can include a first sensor arrangement and a second sensor arrangement as described in U.S. Pat. No. 5,827,963, the entire disclosure of which is incorporated herein by reference. The first sensor arrangement can be positioned above the second sensor arrangement, and each of the sensor arrangements may be affixed to a side wall of the tank, such that the housing the sensor, and the transmitter of each of the sensor arrangements are positioned outside of the tank. Moreover, the sensor of the first sensor arrangement can detect the pressure at the first fluid level via a first opening formed in the side wall of the tank, and the sensor of the second sensor arrangement can detect the pressure at the second fluid level via a second opening formed in the side wall of the tank.
As described-above, the conventional arrangement can be affixed to the tank, e.g., to the side wall of the tank or to the top portion which covers the tank. Specifically, holes or fores may be provided through the side wall or the top of the tank, and the conventional arrangement can be affixed to the side wall or the top portion of the tank using a plurality of securing elements, such as a plurality of metallic nuts and bolts, or protrude therethrough. Nevertheless, in the conventional arrangement, the nuts and one end of each of the bolts are positioned inside the tank. Moreover, such nuts and bolts are metallic, and have roughened surfaces. When the tank is used over a period of time, the roughened surfaces of the nuts and bolts may collect residue, and such residue may adversely affect the sample fluid inside the tank.